Stopcock



Dec. 16, 1969 c. A. PORTER 3,484,077

STOPCOCK Filed May 6, 1966 INVENTOR.

CHARLES pea-FE BY M M aw'wo auevs nited States Patent 0 3,434,077 STOPCQCK Charles A. Porter, Vinelaud, N.J., assignor to Owenslillinois, Inc., a corporation of Ohio Filed May 6, 1966, Ser. No. 548,268 Int. Cl. F3t6k 25/00; B011 3/00 US. Cl. 251-181 10 Claims ABSTRACT OF THE DISCLOSURE A stopcock apparatus for laboratory glassware which includes a glass barrel having an internally tapered bore, an externally tapered plug member which is rotatably positioned within the bore, and a plastic spring cap member which is attached over the beaded edge of the body portion thereby exerting a biasing force pushing the plug into fluid tight sealing engagement with the tapered wall of the bore.

The present invention relates to laboratory glassware and in particular is concerned with a novel valve assembly which is suitable for use as a part of such glassware. The valve of the present invention may be used in various forms such as in stopcocks, burettes, or other laboratory apparatus, however, for purposes of illustrating the invention a stopcock will be used.

evices such as stopcocks utilized in laboratory glassware generally have a glass barrel with a passage therethrough containing a tapered surface and elongated tubular side sections containing one or more centrally located passages that open communicatively in the tapered surface. A glass plug or plug of other material such as a synthetic resin that has a tapered external surface adapted to mate with the internal surface of a tapered barrel is mounted in the barrel and the plug generally has a diametrical passage therethrough which connects communicatively with the tubular side sections of the tapered barrel when the plug is properly aligned. While a diametrical passage has been shown for the purpose of illustrating the instant invention, it will be obvious that the passage through the plug can be located in a plane that is not normal to the longitudinal axis of the plug.

According to one form of the invention, the stopcock plug has a handle which passes through a transverse passage in a portion of the plug that extends through one end of the stopcock body. In order to maintain the plug in a resiliently seated condition in the tapered passage within the stopcock, a resilient spring cap member is arranged about the large end of the glass barrel of the stopcock so that it can exert a biasing force against the plug. The spring cap member that forms a part of the present invention is similar to a snap cap and can be resiliently forced into position over the bulbous bead which forms the peripheral edge of the glass barrel. The

spring cap member has an inwardly radially extending portion that engages circumferentially against the external wall of the plug before the entire washer is snapped into locked position with the glass barrel of the stopcock. The circumferential engagement of the spring cap member against the plug is maintained while it is forced into the locked position thus deflecting a radially inwardly extending portion of the spring cap member to create a thrust in the direction of the longitudinal axis of the plug. The biasing arrangement as afforded by the spring cap member of this invention obviates practically all danger of inadvertent disengagement of the plug from its seat during actual use since such disengagement can be effected only by forcing the snap portion of the cap member from its locked position against and over the beaded end of the glass barrel. The primary object of this invention is to utilize the resilient properties of a spring 3,484,077 Patented Dec. 16, 1969 cap member to maintain a continued force upon a tapered plug positioned within a tapered chamber of a valve mechanism contained within an article generally defined as laboratory apparatus.

An object of the present invention is to provide a simple means of securing a sealing arrangement between the external surface of a tapered plug and the mating conical chamber within a laboratory apparatus article.

Another object of this invention is to produce a stopcock assembly that has a shorter overall dimension thus increasing its versatility in that it can be used in more confined spaces.

A further object of the instant invention is to produce a cheaper stopcock plug assembly in that additional securing means such as holes, threads, nuts, and other parts are not required.

Additional objects and advantages of the invention set forth herein will be apparent from the following description when taken in conjunction with the accompanying drawing which forms a part of the specification, and in which:

FIG. 1 is a perspective view of the assembled stopcock which is illustrative of the invention;

FIG. 2 is an exploded perspective view showing the relationship of the various parts which form the stopcock;

FIG. 3 is a side view partly in cross-section showing the spring cap member as it urges the plug into sealing engagement with the interior of the glass barrel;

FIG. 4 is a fragmentary cross-sectional view through the spring cap member showing the radially inwardly extending portion in the undeformed position;

FIG. 5 is a side view partly in section and similar to FIG. 3 which shows a variation in that the spring cap member is positioned at the small end of the tapered plug; and

FIG. 6 is a side view partly in section and similar to FIG. 5 which shows a modification of the present invention.

The glass barrel of the laboratory apparatus as depicted in the above set forth drawings can be either of vitreous or non-vitreous material such as a synthetic plastic composition or even metal. The plug used in the instant invention is formed from a vitreous material such as glass or from a chemically inert synthetic resin material that is quite stable both chemically and physically at relatively high temperatures and high concentrations of acids or alkalies. The plug is conical or tapered in configuration and generally is self-lubricating with respect to a smooth surface such as the conical interior surface of the barrel into which it mates. The plug material is such that it will retain its shape, however, it can yield slightly under pressure when it is made from a plastic material and is capable of having its surface conform to the contiguous glass surface of the conical bore of the apparatus housing. The resinous plug used to illustrate the present invention is preferably non-porous and forms a fluid tight seal with the tapered bore surface of the housing portion of the apparatus. Even though the plug is resiliently urged into the tapered bore by means of a resilient spring cap member it is easy to rotate during actual use.

The plug is made preferably of a polytetrahaloethylene synthetic resin, polystyrene, or other synthetic resins having the above-described resilient and non-porous characteristics. Plugs possessing the desired physical characteristics can be manufactured from polytetrafluoroethylene and polytrifluorochloroethylene. The preferred material is the first of the above mentioned materials and is sold commercially by the E. I. du Pont de Nemours & Company under the trademark of Teflon.

Referring to the drawing in detail, the stopcock which will be used to illustrate the invention but will not be considered to limit its use thereto is shown in perspective in FIG. 1. The assembly comprises a frusto-conical shaped housing with lateral tubular sections 11 and 12 that are capable of carrying fluid to and from the stopcock. Within housing 10 is a plug the external surface of which mates with the inside of housing 10. Plug 20 is equipped with a handle 30 so that a torque may be applied to the plug for controlling or stopping the flow of fluid through the stopcock. A retaining spring cap member 40 is shown in locked position over the edge of housing 10.

FIG. 2 is an exploded view which shows the parts of the stopcock in disassembled realtionship. Housing 10 is shown with its beaded edge 13 and the frusto-conical interior surface 14. Plug 20 has a frusto-com'cal exterior surface 21 that conforms generally to the interior surface 14 of housing 10. Plug 20 has a passage 22 diametrically located through conical surface 21. As has been mentioned before, it is obvious that passage 22 can be located in a plane other than normal to the longitudinal axis of the plug. It is also contemplated that passage 22 can communicate with additional passageways within the stopcock or else can be one or more separate channels. A neck portion 23 separates and connects conical portion 21 of plug 20 with outermost section 24. Outermost section 24 also has a passage 25 therethrough to accommodate a handle such as 30. Handle is elongated in form, both extremities being slightly tapered as at 31. Additional rings of material depicted at 32 are an integral part of the handle thus providing an easy means for gripping the handle during the application of torque. At the center of handle 30 are raised areas 33 which facilitate engagement with the internal surface of passage 25 of plug 20. The use of a passageway through outermost section 24 and a handle such as 30 provide a convenient means of assembling the plug, however, as will be described later, the handle could be an integral part of the plug.

Spring cap member 40 is shown with its generally cylindrical exterior 41 and its radially inwardly extending part 42 generally at right angles to the cylindrical exterior 41. Located along the surface generated by member 42 is a concentrically positioned indented section 43 which provides a reduced wall thickness in spring cap member 40. While indented section 43 may be necessary to provide the additional resilience required by some plastic materials, indented section 43 may be dispensed with by a proper selection of materials and wall thicknesses. In place of a solid concentric ring portion such as 42, it is conceivable that the present invention will work equally well if ring 42 is formed with a series of radially extending slots thus providing a series of cantilevered fingers to act as a biasing means to keep the plug in sealing engagement with the interior of the stopcock housing.

FIG. 3 is a side view of the stopcock shown partly in section. Plug 20 has its external surface 21 in seated engagement with the frusto-conical interior surface 14 of housing 10. Diametrical passage 22 of plug 20 has its openings in surface 21 in the plane of passages 15 and 16 of tubular sections 11 and 12. In the position as shown it is possible for a fluid to flow unimpeded through the assembly. Accordingly, by rotation of plug 20 the passage 22 may be placed to connect the passages 15 and 16 or may be disposed out of alignment with pass-ages 15 and 16 so that the ends of passages 15 and 16 will be closed by abutting against wall 21 of plug 20.

To keep plug 20 and consequently passage 22 in the same plane as passages 15 and 16 it is necessary that plug 20 cannot shift appreciably in the axial direction of the plug. It is also desirable that plug 20 always remains in sealing engagement with the internal surface 14 of housing 10 so that leaks will not occur between the joining surfaces of the plug and housing during actual use of the apparatus. Spring cap member 40 has an inwardly protruding lip section 44 which can best be seen in FIG. 4. The internal diameter of lip 44 is smaller than the diametrical distance across the beaded end 13 of housing 10.

Lip 44 has been shown as a continuous ring positioned within the cylindrical section of spring cap member 40. While is has not been illustrated in the drawing, it is considered within the scope of the present invention to form a series of radially inward extending serrations or protrusions that would replace the continous ring 44 as depicted in FIG. 4. Thus when spring cap member 40 is brought into axial alignment with beaded end 13 of housing 10, the mismatch in diameters set forth above will require that an axial force be exerted before cap member 40 will snap into engagement with housing 10 as shown in FIG. 3. As cap member 40 is forced into fixed engagement with the beaded edge 13 of housing 10, the radially inwardly protruding portion 42 will come into contact with the tapered neck section 23 of plug 20. Thus it is evident that portion 42 must deflect in an axial direction so that cap member 40 can snap into position. This deflection produces a continued constant biasing force which keeps exernal surface 21 of plug 20 in tight engagement with wall 14 of housing 10. The amount of resiliency of portion 42 is dependent upon the material selected for spring cap member 40, the overall thickness of portion 42, and to some extent upon a groove such as 43.

FIG. 5 is a modification of the invention where it is important to keep the overall width of the assembly at a minimum. A housing 50 is shown with a plug 51 positioned therein. The ordinary handle assembly has been removed to reduce the overall width and in its place has been inserted an internal wrenching cavity 52. Cavity 52 is an ordinary hex surfaced interior that will accommodate the driving surface of a tool such as an Allen wrench. In this manner, the width of the assembly is reduced and the position of the stopcock cannot be inadvertently turned from what could be a critical setting during the actual use of the apparatus. To effect the tight engagement of plug 52 with the frusto-conical internal surface of housing 50, the snap spring cap of the present invention is placed over the beaded edge 53 which is located at the small end of housing 50. The radially inward edge 54 which is shown in the undeformed position as dotted lines in FIG. 5 is forced into engagement with a concentric groove 55 which has been placed in the small end of plug 51. Thus it is readily apparent that this form of the invention possesses all the advantages of the ordinary stopcock plus the additional features of space saving plus controlled access to the rotation of the plug within the internal bore of the housing. An additional advantage of biasing the plug on the small end of the tapered section is that the handle can be molded as an integral part of the plug assembly. While this is not shown in the drawing, it can be readily visualized by reference to FIGS. 1 and 3.

FIG. 6 represents a further modification of the present invention wherein a housing 60 is shown with a plug 61 which is similar to plug 51 as shown in FIG. 5. Plug 61. however, does not have a concentric groove at the small end of the plug. Plug 61 is kept in biased relationship against the internal wall 62 of housing 69 by spring cap member 63 which fits in locked engagement over the protruding edge 64 of housing 60. In this variation of the invention, spring cap member 63 contains a slight bead 65 at the inside edge of that portion the cap that is located nearest to the longitudinal axis of the cap and which biases against the exterior surface of plug 61. The usual internal wrenching surface as heretofore described is used in this embodiment if desired. Easy access can be gained by a tool since it will pass readily through the central opening within spring cap member 61.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What is claimed is:

l. A laboratory glassware article including a body portion having an elongated tapered internal bore located therein, an externally tapered plug member rotatably positioned within said bore and in sealing arrangement with the surface thereof, and resilient means attached to said body portion and in engagement with said plug whereby said plug is resiliently urged into continued sealing engagement with said internal bore.

2. A laboratory glassware article including a body portion having an elongated tapered internal bore therein, transversely aligned passageways positioned on opposite sides of said body and in communication with said bore, an externally tapered plug member rotatably positioned and confined within said bore and having a portion thereof unconfined by said body, said plug having at least one transversely oriented passageway that can be brought into communication with the passageways of said body portion by rotation of the plug, a spring cap member held in locked engagement with said body portion and biased against the unconfined portion of said plug to resiliently urge the plug into continued sealing engagement with the internal bore of said body portion.

3. A laboratory glassware article as claimed in claim 2 wherein said spring cap member is plastic and is attached over a beaded edge of the body portion of said article.

4. A laboratory glassware article as claimed in claim 2 wherein said spring cap member has a hollow cylindrical section containing therein a radially inward protmsion whose internal diameter is smaller than the external diameter of the beaded portion of said hollow body over which it engages, and wherein said cap has a part extending radially inward and contains an aperture that is located normal and concentrically with respect to the longitudinal axis of said cap.

5. A laboratory glassware article as claimed in claim 4 wherein the part of the cap that extends radially inward has located therein a section for controlling the deflection of said radially inward extending part, said section being concentric with respect to the longitudinal axis of said cap.

6. A laboratory glassware article as claimed in claim 5 wherein internal wrenching means is located within said plug along the longitudinal axis thereof for rotating said plug.

7. A laboratory glassware article as claimed in claim 2 wherein the unconfined portion of the plug terminates with a handle and wherein the unconfined section of the plug between the handle and the confined portion of said plug has a taper opposite in slope with respect to the taper of that portion of the plug situated within said body and wherein said spring cap member is in contact with the unconfined tapered section of said plug.

8. A laboratory glassware article as claimed in claim 7 wherein said spring cap member is plastic and is attached over a beaded edge of the body portion of said article.

9. A laboratory glassware article as claimed in claim 8 wherein said spring cap member has a hollow cylindrical section containing therein a radially inward protrusion whose internal diameter is smaller than the external diameter of the beaded portion of said body over which it engages, and wherein said cap has a part extending radially inward and contains an aperture that is located normal and concentrically with respect to the longitudinal axis of said cap.

10. A laboratory glassware article as claimed in claim 8 wherein the part of the cap that extends radially inward has located therein a section for controlling the defiection of said radially inward extended part, said section being concentric with respect to the longitudinal axis of said cap.

References Cited UNITED STATES PATENTS 3,269,696 8/1916 Norton 25ll8l MORRIS O. WOLK, Primary Examiner ELLIOTT A. KATZ, Assistant Examiner U.S. Cl. X.R. 23-292 

